Prior art container closures having a pour spout or the like are disclosed in U.S. patent application Ser. No. 08/332,140 (filed Oct. 31, 1994), Ser. No. 08/633,225 (filed Apr. 16, 1996), Ser. No. 08/687,149 (filed Jul. 24, 1996) and U.S. Pat. Nos. 5,104,008 and 5,465,876. Such prior spout closures provide tamper evidency which have tamper evident pour spouts but have not been leak proof at spout closure interface. Generally, prior art push-pull spouts that are reusable do not provide effective sealing at the juncture between the spout opening and the plug positioned in the opening when the spout is closed. Because of the very small diameter of the opening and the concern for safety, it is not possible to add non-integrated sealing means.
Snap-on tamper evident closures are also well known in the prior art for use on blow-molded milk containers and on fruit juice bottles. Illustrative of the prior art are U.S. Pat. Nos. 4,934,546, 4,844,268, 4,815,620, 4,589,561, 4,676,389, 4,676,389, 4,593,830, 4,699,268, 4,700,860, 4,202,455, 5,036,991, 3,940,004 and 4,066,182. Generally, these closures are shaped to engage the neck of a thin-walled blow molded plastic bottle used for milk, bottled water or juices. The neck of these bottles is typically formed with an inwardly turned flange at its upper end and includes an upper and lower external locking bead around the circumference of the neck to securely mate the closure thereto. Tamper evident closures of the prior art typically include a circular closure disk with a depending upper annular skirt and a lower depending annular skirt containing a tamper evident tear strip. Positioned on the internal walls of the respective skirt are upper and lower locking beads or flanges which are positioned to engage the external locking beads on the upper and lower portion of the neck of the bottle. Normally, the beads on the closure ride over the beads on the neck and provide "locking" of the closure on the container neck by the beads impeding sliding travel of the closure thereover. In addition, the prior art closures include a valve means depending from the inner surface of the closure disk which is adapted to engage the internal neck portion to create a seal at the mouth of the container. While the prior art snap-on closures provide evidence that a closure has been removed from the container when the tamper-evident band has been removed it is possible to remove many of the commercially available snap-on closures without removing the band. Moreover, when the tamper evident band having the lower locking bead has been removed, these caps do not provide a tight closure or effective seal. The removal of the lower skirt portion along with the tamper evidency deprives the cap of the primary locking means. This is typically not a problem with containers which are not reused, but with containers that are to be used or are not dispensed upon the initial opening the single remaining locking mechanism does not provide a leak proof seal.
Accordingly, it is an object of the present invention to provide a substantially leak proof tamper-evident closure combining a reusable, push-pull spout with a snap-on tamper evident closure which is substantially tamper proof.
Accordingly, it is an object of the present invention to provide an effective seal for a push-pull spout for reusable containers, combined with a snap-on tamper evident closure which provides a secure closure which is substantially tamper proof.
It is a further object of the present invention to provide a substantially leak proof push-pull pour spout for reusable containers, combined with a snap-on tamper evident closure having a first or upper locking means which provides additional locking forces when unauthorized removal is attempted.
It is a further object of the present invention to provide a substantially leak proof push-pull pour spout for reusable containers, combined with a snap-on tamper evident closure having an upturned internal locking flange to lock onto the upper locking bead of the container and having a push-pull resealable tamper evident pour spout.
It is a further object of the present invention to provide a substantially leak proof push-pull pour spout for reusable containers, combined with a snap-on tamper evident closure having a first locking member with a reverse internal flange which projects towards the mouth of the neck.
It is a further object of the present invention to provide a substantially leak proof push-pull pour spout for reusable containers, combined with a snap-on tamper evident closure that forms a secure seal upon reuse when the second skirt or tamper evident band is removed from the closure for reuse of the container.
It is a further object of the present invention to provide a substantially leak proof push-pull pour spout for reusable containers, combined with a snap-on tamper evident closure which is usable on existing neck finishes with little or no modification.